| 摘要 |
PROBLEM TO BE SOLVED: To provide the communication current supply circuit of simpler circuit constitution in the telephone set of a subscriber circuit system. SOLUTION: This communication current supply circuit is provided with a constant current circuit 10 provided between power source wiring 41 and a terminal L1 of the telephone set, a main resistor 11 provided between a ground wiring 42 and a terminal L2 of the telephone set and an AC impedance circuit 51 provided between the telephone set terminal L1 and the ground wiring 42. The main resistor 11 is designed, so as to achieve the role of keeping balance with the AC impedance circuit 51 and securing impedance to AC signals generated at the time of communication. |
